Vehicle seat

ABSTRACT

A vehicle seat includes right and left side frames 10, and an elastic member (cushion spring 20) run between the right and left side frames 10. The right and left side frames 10 include side walls 11 disposed opposite to each other in a lateral direction, and flange portions (upper flange portions 12) respectively extending laterally inward from the side walls 11, and the elastic member is attached to the flange portions.

TECHNICAL FIELD

The present invention relates to a vehicle seat.

BACKGROUND ART

Conventionally, there is known a vehicle seat including right and leftside frames and a cushion spring run between the right and left sideframes (for example, Japanese Laid-open Patent Application, PublicationNo. 2010-167022). To be more specific, in this technique, the cushionspring is attached to side walls, which are opposite to each other inthe lateral direction, of the right and left side frames.

SUMMARY OF THE INVENTION

However, there are drawbacks in the above technique that no structuralobject can be disposed between the side walls because the cushion springis attached to the side walls and that the shape of the side wallscannot be determined as desired.

In view of the above, a first object of the present invention is toprovide a vehicle seat, in which a structural object can be disposedbetween the side walls of the side frames to which the cushion spring(elastic member) is attached, and in which the shape of the side wallscan be determined as desired.

Further, the present invention seeks to suppress deformation of aportion to which the cushion spring is attached. The present inventionalso seeks to favorably support an occupant by the cushion spring.

Further, the present invention seeks to effectively utilize a spacebetween the cushion spring and the side frames. The present inventionalso seeks to prevent the cushion spring from interfering with a partprovided in the vicinity of the side frames when the cushion spring isattached to the side frames.

Further, the present invention seeks to favorably keep the engagementbetween the cushion spring and the side frames. The present inventionalso seeks to facilitate the work for attaching the cushion spring tothe side frames.

Further, the present invention seeks to cause the side frames tofavorably receive a load from the cushion spring. The present inventionalso seeks to downsize the vehicle seat in the upper-lower direction.

Further, the present invention seeks to enhance the rigidity of aportion of the side frame to which the cushion spring is engaged.

Conventionally, there is also known a vehicle seat including a seatcushion frame, a cushion pad supported by the seat cushion frame, and askin material by which the cushion pad is covered (for example, JapaneseLaid-open Patent Application, Publication No. 2002-66174). To be morespecific, in this technique, the seat cushion frame is provided with awire-like skin attachment member, and hooks provided at an end portionof the skin material are hooked on the skin attachment member, wherebythe attachment of the skin member is carried out.

However, there is a drawback in this technique that the frame structureis complicated because the skin attachment member is provided on theseat cushion frame.

In view of the above, a second object of the present invention is tosimplify the frame structure of the vehicle seat.

Further, the present invention seeks to downsize the cushion pad and tosuppress deformation of the skin attachment member. The presentinvention also seeks to facilitate the work for attaching the skinmaterial, to enhance the rigidity of the cushion pad, and to prevent theengagement portion from coming off the skin attachment member.

Conventionally, there is also known a vehicle seat in which the seatcushion pad has a through-opening for inserting a harness member for aseating sensor (for example, Japanese Laid-open Patent Application,Publication No. 2012-140064). Further, there is known a vehicle seatincluding an elastic member for supporting the seat cushion pad from thelower side of the seat cushion pad (for example, Japanese Laid-openPatent Application, Publication No. 2008-080904).

However, in the configuration in which the seat cushion pad having thethrough-opening is supported by the elastic member from the lower sideof the seat cushion pad, if a portion around the through-opening is notfavorably supported by the elastic member, there may be a concern thatthe portion around the through-opening deforms and a load is applied tothe harness member.

In view of the above, a third object of the present invention is toreduce a load applied to the harness member to be inserted into thethrough-opening fainted in the seat cushion pad.

Further, the present invention seeks to facilitate the work forinserting the harness member into the through-opening and to suppressinterference between the harness member and the elastic member. Thepresent invention also seeks to favorably support the seat cushion padby the elastic member, to reduce the weight of the seat cushion pad, andto reduce uncomfortable feeling of the occupant due to the presence ofthe through-opening.

According to the present invention which may achieve the first object, avehicle seat comprises: right and left side frames; and an elasticmember run between the right and left side frames and configured tosupport an occupant. The right and left side frames comprise: side wallsdisposed opposite to each other in a lateral direction; and flangeportions respectively extending laterally inward from the side walls,and the elastic member is attached to the flange portions.

With this configuration, since the elastic member is attached to theflange portions extending laterally inward from the side walls, forexample, as compared with the configuration in which the elastic memberis attached to the side walls, it is possible that a structural objectis disposed between the side walls and that the shape of the side wallsis determined as desired.

In the above configuration, if the right and left side frames constitutea seat cushion frame, and each of the flange portions has a firstengagement opening formed therein with which an engagement portionformed at an end portion of the elastic member is engaged, it ispreferable that the elastic member is inserted through and engaged withthe first engagement opening from a lower side to an upper side of thefirst engagement opening.

With this configuration, since the elastic member is inserted throughand engaged with the first engagement opening from the lower side to theupper side of the first engagement opening, for example, as comparedwith the configuration in which the elastic member is inserted throughand engaged with the first engagement opening from the upper side to thelower side of the first engagement opening, it is possible to suppressdeformation of an distal end portion of the flange portion when a loadis applied from the elastic member to the distal end portion.

In the above configuration, it is preferable that the flange portion isan upper flange portion extending laterally inward from an upper endthereof.

With this configuration, since the elastic member is supported by theupper flange portion which is less likely to deform by a downward load,it is possible to favorably support the occupant by the elastic member.

In the above configuration, it is preferable that the elastic membercomprises a middle portion extending in the lateral direction, andslanted portions respectively extending obliquely upward from right andleft ends of the middle portion.

With this configuration, since the both end sides of the elastic memberare formed as the slanted portions, the elastic member can fit thebuttocks of the occupant, so that the buttocks of the occupant can befavorably supported by the elastic member.

In the above configuration, the vehicle seat may comprise a heightadjustment mechanism disposed between the slanted portions and the sidewalls and configured to adjust a height of the seat cushion frame.

With this configuration, since the height adjustment mechanism isdisposed between the slanted portions of the elastic member and the sidewalls, it is possible to effectively utilize the space between theslanted portions and the side walls.

In the above configuration, if the elastic member is disposed at aposition rearward of a front end portion of the height adjustmentmechanism and frontward of a center of the height adjustment mechanismin a front-rear direction, it is preferable that the elastic member isengaged with the first engagement opening from a rear side of the firstengagement opening.

With this configuration, since the elastic member is configured to beengaged with the first engagement opening from the rear side of thefirst engagement opening, it is possible to prevent the elastic memberfrom interfering with the structure in the vicinity of the front endportion of the height adjustment mechanism (e.g., front link) when theelastic member is engaged with the first engagement opening.

In the above configuration, if the elastic member is disposed at aposition frontward of a rear end portion of the height adjustmentmechanism and rearward of a center of the height adjustment mechanism ina front-rear direction, it is preferable that the elastic member isengaged with the first engagement opening from a front side of the firstengagement opening.

With this configuration, since the elastic member is configured to beengaged with the first engagement opening from the front side of thefirst engagement opening, it is possible to prevent the elastic memberfrom interfering with the structure in the vicinity of the rear endportion of the height adjustment mechanism (e.g., rear link) when theelastic member is engaged with the first engagement opening.

The above configuration may further comprise a second engagement openingwith which an end portion of the engagement portion is engaged with theengagement portion of the elastic member being inserted from the upperside to the lower side, and it is preferable that the end portion of theengagement portion of the elastic member is formed to extend to one sideaway from an imaginary line extending through the first engagementopening and the second engagement opening, and that the secondengagement opening has an end portion remote from the first engagementopening and extending to the other side away from the imaginary line.

With this configuration, since the end portion of the engagement portionis formed to extend to one side away from the imaginary line extendingthrough the first engagement opening and the second engagement opening,and the end portion of the second engagement opening that is remote fromthe first engagement opening is formed to extend to the other side awayfrom the imaginary line, the end portion of the engagement portion andthe second engagement opening can be located away from each other. Thismakes it possible to favorably keep the engagement between the elasticmember and the side frames.

In the above configuration, if the first engagement opening and thesecond engagement opening are arranged in alignment with each other in afront-rear direction, it is preferable that the end portion of theengagement portion of the elastic member is formed to face laterallyinward and that the end portion of the second engagement opening remotefrom the first engagement opening is formed to face laterally outward.

With this configuration, since the end portion of the engagement portionof the elastic member is formed to face laterally inward, the engagementportion can be formed as a C-shaped configuration, so that the work forattaching the elastic member to the first engagement opening and thesecond engagement opening can be eased.

In the above configuration, if the elastic member comprises twofront-side and rear-side elastic members provided spaced apart in afront-rear direction, it is preferable that the flange portion has afront-side portion to which the front-side elastic member is attachedand a rear-side portion to which the rear-side elastic member isattached, and a lateral width of the front-side portion is greater thanthat of the rear-side portion.

With this configuration, since the rigidity of the front-side portion ofthe flange portion can be enhanced by making the width of the front-sideportion to which the front-side elastic member is attached greater thanthat of the rear-side portion to which the rear-side elastic member isattached, even if a large load is applied from the occupant to thefront-side elastic member, for example, in a collision, the front-sideportion of the flange portion can favorably receive the large loadapplied from the front-side elastic member.

In the above configuration, it is preferable that a recess portion isformed between the first engagement opening and the second engagementopening; the recess portion is recessed downward and extends from thefirst engagement opening to the second engagement opening.

With this configuration, since the recess portion is formed between thefirst engagement opening and the second engagement opening, theprotrusion distance of the elastic member by which the elastic memberprotrudes upward from the upper surface of the flange portion can bedecreased. This can downsize the vehicle seat in the upper-lowerdirection.

The above configuration may further comprise a cover member configuredto cover the recess portion and placed on the engagement portion of theelastic member.

With this configuration, since the cover member is placed on theengagement portion of the elastic member that is disposed in the recessportion, the engagement portion of the elastic member can be sandwichedbetween the recess portion and the cover member. This can favorably keepthe engagement between the elastic member and the engagement openings.

In the above configuration, it is preferable that the side frame has afirst portion located frontward of the first engagement opening and asecond portion located rearward of the first engagement opening and thatthe vehicle seat further comprises a reinforcement member extending fromthe first portion to the second portion and welded to the first portionand the second portion.

With this configuration, since the first portion and the second portionrespectively located frontward and rearward of the first engagementopening are reinforced by the reinforcement member, the rigidity in thevicinity of the first engagement opening can be enhanced.

According to the present invention which may achieve the second object,a vehicle seat comprises: a cushion pad and a skin material covering thecushion pad, wherein a skin attachment member is provided at a reverseside of the cushion pad, and an engagement portion provided at an endportion of the skin material is engageable with the skin attachmentmember.

With this configuration, since the skin attachment member is provided atthe reverse side of the cushion pad, as compared with the conventionalconfiguration in which the skin attachment member is provided on theframe, it is possible to simplify the frame structure.

In the above configuration, a recess portion may be provided at areverse surface of the cushion pad, and the skin attachment member maybe configured to include a retention portion embedded and retained inthe cushion pad, and an engaged portion exposed in the recess portionand engaged with the engagement portion.

With this configuration, since the skin attachment member can beembedded into the cushion pad without protruding from the reversesurface of the cushion pad, it is possible to downsize the cushion pad.

In the above configuration, the recess portion may comprise a pluralityof recess portions arranged spaced apart along a direction in which theskin attachment member extends, and the retention portion of the skinattachment member may be embedded and retained in a middle portionlocated between the plurality of recess portions.

With this configuration, since the skin attachment member can beretained by the plurality of middle portions, for example, as comparedwith the embodiment in which the recess portion extends long in adirection in which the skin attachment member extends, it is possible tosuppress deformation of the skin attachment member.

In the above configuration, if a sheet member for improving the rigidityof the cushion pad is provided on the reverse surface of the cushionpad, the sheet member may comprise cutaway portions for exposing therecess portions, and a middle reinforcement portion disposed to overlapthe middle portion.

With this configuration, since the rigidity of the middle portion isimproved by the middle reinforcement portion of the sheet member, it ispossible to further suppress the deformation of the skin attachmentmember.

If the above configuration further comprises an elastic member extendingin a direction from one end to another end of the cushion pad andincluding longitudinal and transverse dimensions to support the cushionpad from the reverse side thereof, the skin attachment member may bedisposed so as not to overlap the elastic member as viewed from thereverse side.

With this configuration, the work for attaching the skin material can beeased because when the engagement portion of the skin material isattached to the skin attachment member, the elastic member does notobstruct the attachment.

In the above configuration, the elastic member may comprise a pluralityof elastic members arranged in a transverse direction thereof, and theskin attachment member may be disposed outside the plurality of elasticmembers in the transverse direction.

With this configuration, even when the engagement portion of the skinmaterial approaches the skin attachment member in the transversedirection from outside the elastic members, as the elastic members arenot present outside the skin attachment member in the transversedirection, the work for attaching the skin material can be easedfurther, in comparison, for example, with the configuration in which theskin attachment member is disposed between the plurality of elasticmembers.

In the above configuration, if the elastic member is an S-shaped springhaving a plurality of turns made in the transverse direction, theplurality of turns of the S-shaped spring include a bent portionprotruding away from the recess portions, and the middle portion and thebent portion may be arranged in a same position in a longitudinaldirection of the elastic member.

Herein, the term “same position” indicates that a portion of the middleportion and a portion of the bent portion are located in the sameposition.

With this configuration, since the middle portion is disposed in an openportion of the S-shaped spring, it is possible to enhance the rigidityof a portion of the cushion pad which is located in an open space of theopen portion of the S-shaped spring, in comparison, for example, withthe configuration in which the recess portion is formed to extend longin the longitudinal direction.

If the above configuration further comprises an elastic member extendingin a direction from one end to another end of the cushion pad andincluding longitudinal and transverse dimensions to support the cushionpad from the reverse side thereof, the elastic member may be disposeddirectly behind a portion of the skin attachment member.

With this configuration, even if a local load is applied in the vicinityof the skin attachment member of the cushion pad, the elastic member cansuppress sinking of the skin attachment member. Accordingly, it ispossible to prevent the engagement portion from coming off the skinattachment member due to sinking of the skin attachment member.

According to the present invention which may achieve the third object, avehicle seat comprises a seat cushion and a seat back. The seat cushioncomprises a seat cushion pad having a through-opening for inserting aharness member, and an elastic member extending in a direction from oneend to another end of the seat cushion pad and including longitudinaland transverse dimensions to support the cushion pad from a lower sideof the seat cushion pad, wherein the elastic member and thethrough-opening are arranged to intersect one vertical plane extendingin a longitudinal direction of the elastic member.

With this configuration, since a portion in the vicinity of thethrough-opening is supported by the elastic member, deformation of thethrough-opening of the seat cushion pad can be suppressed and a loadapplied to the harness member can be reduced.

In the above configuration, the through-opening may be disposed so asnot to overlap the elastic member as viewed from the lower side.

With this configuration, the work for inserting the harness member intothe through-opening can be eased because the elastic member does notobstruct the work. Further, since the through-opening and the elasticmember do not overlap each other, interference between the harnessmember and the elastic member can be suppressed.

In the above configuration, the elastic member may be formed to extendalong a peripheral edge of the through-opening.

This configuration makes it possible to more favorably support theportion in the vicinity of the through-opening by the elastic member.

In the above configuration, the elastic member may be an S-shaped springhaving a plurality of turns made in a transverse direction of theelastic member.

With this configuration, the seat cushion pad can be favorably supportedby the S-shaped spring.

The above configuration may comprise a pair of front-side and rear-sideS-shaped springs extending laterally and provided spaced apart from eachother in the front-rear direction, and the through-opening may beprovided in a position corresponding to the front-side S-shaped spring,and further a portion of the front-side S-shaped spring which is locatedto surround the through-opening may open rearward.

With this configuration, since the through-opening is provided in theposition corresponding to the front-side S-shaped spring, which is lesslikely to receive a load from the occupant than the rear-side S-shapedspring to which a large load is applied from the occupant, it ispossible to reduce a load applied to the harness member whilesuppressing deformation of the through-opening. Further, since theportion of the front-side S-shaped spring which is located to surroundthe through-opening opens rearward, even if the through-opening and theharness member located in the through-opening are pulled rearward andmoved when the rear portion of the seat cushion pad is deeply sunk bythe load from the occupant, interference between the harness member andthe S-shaped spring can be suppressed.

In the above configuration, the through-opening may be formed such thata lower-side opening thereof is larger than an upper-side openingthereof.

With this configuration, for example, as compared with the configurationin which the through-opening is formed to extend vertically straight,the weight of the seat cushion pad can be reduced for the amountcorresponding to the extended lower-side portion of the through-opening.Further, since the upper-side opening of the through-opening is smaller,it is possible to reduce uncomfortable feeling experienced by theoccupant when he/she sits on the seat cushion pad and feels the presenceof the through-opening, for example, as compared with the configurationin which the upper-side opening of the through-opening is enlarged toreduce the weight.

BRIEF DESCRIPTION OF DRAWINGS

FIG. 1 is a perspective view of a car seat according to the firstembodiment.

FIG. 2 is a perspective view of a seat frame embedded in the car seat.

FIG. 3 shows a structure around engagement openings and a cushion springand includes: (a) a perspective view thereof, and (b) a top viewthereof.

FIG. 4 is a sectional view taken along the line I-I of FIG. 3(a).

FIG. 5 shows a side frame as viewed from the laterally inner side andincludes: (a) a side view thereof, and (b) a sectional view of theportion indicated by arrow II of FIG. 5(a).

FIG. 6 is a perspective view of the seat frame embedded in the car seataccording to the second embodiment of the present invention.

FIG. 7 is a perspective view of a seat cushion pad and a coarse blanketas viewed from the bottom side.

FIG. 8 is a bottom view of S-shaped springs and the seat cushion pad asviewed from the bottom side.

FIG. 9 includes (a) an enlarged bottom view showing a portion around askin attachment wire, and (b) a sectional view taken along the line ofFIG. 9(a).

FIG. 10 is a bottom view of the skin attachment wire according to thefirst modified embodiment as viewed from the bottom side.

FIG. 11 includes (a) a sectional view of the skin attachment wireaccording to the second modified embodiment taken along the planeorthogonal to the lateral direction, and (b) a sectional view takenalong the line IV-IV of FIG. 11(a).

FIG. 12 is a perspective view of the seat frame embedded in the car seataccording to the third embodiment of the present invention.

FIG. 13 includes (a) a perspective view of the seat cushion pad asviewed from the bottom side, and (b) a sectional view showing a portionaround the through-opening.

FIG. 14 is a bottom view of the S-shaped springs and the seat cushionpad as viewed from the bottom side.

FIG. 15 is a perspective view of the skin attachment member and a skinmaterial as viewed from the bottom side.

FIG. 16 is a bottom view showing an embodiment in which thethrough-opening is disposed in a position outside the width of theS-shaped spring in the front-rear direction.

DESCRIPTION OF EMBODIMENTS

Various embodiments of the present invention will be described in detailwith reference made to the drawings where necessary,

First Embodiment

With reference to FIGS. 1 to 5, the first embodiment of the presentinvention will be described. In the following description, the overallstructure of a car seat as an example of a vehicle seat will bedescribed briefly, and then characterizing features of the presentinvention will be described in detail.

As seen in FIG. 1, the car seat S is a seat used in a driver's seat ofan automobile, and mainly includes a seat cushion S1, a seat back S2,and a headrest S3.

A seat frame F as shown in FIG. 2 is embedded in the seat cushion S1 andthe seat back S2. The seat frame F mainly includes a seat cushion frameF1 constituting a frame of the seat cushion S1, and a seat back frame F2constituting a frame of the seat back S2. The seat cushion S1 isconfigured such that the seat cushion frame F1 is covered with a seatcushion pad made of a cushion material such as urethane foam, and a skinmaterial made of synthetic leather or fabric. The seat back S2 isconfigured such that the seat back frame F2 is covered with a seat backpad made of a cushion material, and a skin material made of syntheticleather or fabric.

A seat cushion frame F1 is a frame in the shape of an approximatelyrectangular configuration, and is installed on sliders SL; the slidersSL are respectively supported by a pair of right and left slide rails SRprovided on a floor of an automobile so as to be slidable in thefront-rear direction with respect to the slide rails SR. Accordingly,the position of the car seat S is adjustable in the front-reardirection.

A lower portion of the seat back frame F2 is rotatably connected to arear portion of the seat cushion frame F1 via a reclining mechanism RL.Accordingly, the seat back S2 is tiltable in the front-rear directionwith respect to the seat cushion S1.

In the description, the front/rear (frontward/rearward), right/left(lateral), and upper/lower directions are designated as from the viewpoint of an occupant seated on the car seat S without tilting down theseat back S2 by the reclining mechanism RL.

Next, the seat cushion frame F1 will be described in detail.

The seat cushion frame F1 mainly includes a pair of right and left sideframes 10, two cushion springs 20 (as an example of an elastic member)run between the right and left side frames 10, a pan frame 30 connectingfront portions of the side frames 10, and a connecting pipe 40connecting rear end portions of the side frames 10.

The right and left side frames 10 are frames extending in the front-reardirection and made of metal: the right and left side frames 10 arelaterally spaced apart from each other. As seen in FIGS. 3 to 5, theright and left side frames 10 include right and left side walls 11disposed opposite to each other in the lateral direction, upper flangeportions 12 as an example of flange portions, and lower flange portions13.

The upper flange portion 12 and the lower flange portion 13 are formedto extend laterally inward from the upper end and the lower end of theside wall 11. Further, the two cushion springs 20 are attached to theupper flange portion 12 such that these cushion springs 20 are spacedapart from each other in the front-rear direction.

As described above, since the cushion springs 20 are attached to theupper flange portions 12 configured to extend laterally inward from theside walls 11, for example, as compared with the configuration in whichthe cushion springs are attached to the side walls, it is possible thata height adjustment mechanism 50 to be described later is disposedbetween the side walls 11 at a position adjacent to the side walls 11and that the shape of the side walls 11 is determined as desired.Further, since the cushion springs 20 are attached not to the lowerflange portions 13 but to the upper flange portions 12 which is unlikelyto deform by a downward load, it is possible to favorably support theoccupant by the cushion springs 20.

To be more specific, engagement openings 12A, 12B are formed in theupper flange portion 12; an approximately C-shaped engagement portion 21(to be described later) of the cushion spring 20 is engageable with theengagement openings 12A, 12B. Each of the engagement openings 12A, 12Bincludes a first engagement opening A1, B1 and a second engagementopening A2, B2, which are arranged in line in the front-rear direction.

For details, the first engagement opening A1, B1 is an opening forinserting the engagement portion 21 of the cushion spring 20 in adirection from the lower surface to the upper surface of the upperflange portion 12; the first engagement opening A1, B1 is configured tobe engageable with a proximal portion 21 b (i.e., a connecting portionfor connecting a slanted portion 23) of the engagement portion 21 in astate where the engagement portion 21 is attached to the engagementopening 12A, 12B. The second engagement opening A2, B2 is an opening forinserting the engagement portion 21 of the cushion spring 20 in adirection from the upper surface to the lower surface of the upperflange portion 12; the second engagement opening A2, B2 is configured tobe engageable with an end portion 21 a of the engagement portion 21 in astate where the engagement portion 21 is attached to the engagementopening 12A, 12B.

For more details, in a state where the engagement portion 21 is attachedto the engagement opening 12A, 12B, the end portion 21 a of theengagement portion 21 is formed to face laterally inward (see FIG. 3(b)). In other words, the end portion 21 a of the engagement portion 21is bent to extend to one side away from an imaginary line LA, LBextending through the first engagement opening A1, B1 and the secondengagement opening A2, B2. Accordingly, it is possible to favorably keepthe engagement between the cushion spring 20 and the side frame 10.

Further, the rear end portion B21 (i.e., the end portion opposite to andremote from the first engagement opening B1) of the second engagementopening B2 of the rear-side engagement opening 12B is formed to facelaterally outward. In other words, the rear end portion B21 of thesecond engagement opening B2 is formed to extend to the other side(i.e., direction opposite to the direction in which the end portion 21 aof the engagement portion 21 extends) away from the imaginary line LB.

As described above, since the direction in which the end portion 21 a ofthe engagement portion 21 extends and the direction in which the rearend portion B21 of the second engagement opening B2 extends are oppositeto each other, the end portion 21 a of the engagement portion 21 and therear end portion B21 of the second engagement opening B2 are locatedaway from each other. Accordingly, it is possible to favorably keep theengagement between the cushion spring 20 and the side frame 10.

Further, since the end portion 21 a of the engagement portion 21 isformed to face laterally inward, the engagement portion 21 can be formedas a C-shaped configuration, so that the work for attaching the cushionspring 20 to the first engagement opening A1, A2 and the secondengagement opening A2, B2 can be eased.

Further, a recess portion 12C configured to be recessed downward isformed between the first engagement opening A1, B1 and the secondengagement opening A2, B2. The recess portion 12C is shaped as anapproximately semi-cylindrical configuration and extends from the firstengagement opening A1, B1 to the second engagement opening A2, B2.

As described above, since the recess portion 12C is formed between thefirst engagement opening A1, B1 and the second engagement opening A2,B2, the protrusion distance of the cushion spring 20 by which thecushion spring 20 protrudes upward from the upper surface of the upperflange portion 12 can be decreased (see FIG. 4). This can downsize thecar seat S in the upper-lower direction.

Further, the upper flange portion 12 has a front-side portion 12D inwhich the front-side engagement opening 12A is formed and a rear-sideportion 12E in which the rear-side engagement opening 12B is formed, andthe lateral width of the front-side portion 12D is greater than that ofthe rear-side portion 12E.

As described above, since the upper flange portion 12 is formed suchthat the lateral width of the front-side portion 12D is greater thanthat of the rear-side portion 12E, the rigidity of the front-sideportion 12D of the upper flange portion 12 can be enhanced. Accordingly,even if a large load is applied from the occupant to the front-sidecushion spring 20A, the load applied from the front-side cushion spring20A can be favorably received by the widened front-side portion 12D ofthe upper flange portion 12.

Further, a reinforcement rod 60 as an example of a reinforcement memberis welded to the side wall 11 of the side frame 10; the reinforcementrod 60 has a meandering shape and extends in the front-rear direction.To be more specific, the reinforcement rod 60 includes a first curvedportion 61 having an approximately U-shaped configuration which openslaterally inward, and a second curved portion 62 consecutively extendingfrom the rear end portion of the first curved portion 61 and having anapproximately U-shaped configuration which opens laterally inward.

The first curved portion 61 is formed to extend from a first portion 81located frontward of the rear-side engagement opening 12B to a secondportion 82 located rearward of the rear-side engagement opening 12B, andboth ends of the first curved portion 61 are welded to the first portion81 and the second portion 82, respectively. With this configuration inwhich the first portion 81 and the second portion 82 respectivelylocated frontward and rearward of the rear-side engagement opening 12Bare reinforced by the reinforcement rod 60, the rigidity in the vicinityof the rear-side engagement opening 12B can be enhanced.

According to this embodiment, in particular, the first curved portion 61is welded to the side wall 11 corresponding to the narrowed rear-sideportion 12E. Accordingly, in this embodiment, the rigidity in thevicinity of the narrowed rear-side portion 12E can also be enhanced bythe reinforcement rod 60.

The two cushion springs 20 arranged in the front-rear direction aresprings for receiving a load from the occupant, and they have similarstructures. To be more specific, the cushion spring 20 is an S-spring(wave spring or zigzag spring) extending laterally with a plurality ofturns made in the front-rear direction; as seen in FIG. 4, the S-shapedspring includes a middle portion 22 extending in the lateral direction,slanted portions 23 extending obliquely upward (laterally outward andupward) from right and left ends (only one end is shown in the figure)of the middle portion 22, and engagement portions 21 provided atlaterally outer ends of the slanted portions 23.

With this configuration in which the both end sides of each of thecushion springs 20 are formed as the slanted portions 23, the cushionsprings 20 can fit the buttocks of the occupant, so that the buttocks ofthe occupant can be favorably supported by the cushion springs 20.

Further, a portion of the height adjustment mechanism 50 configured toadjust the height of the seat cushion frame F1 is disposed between theslanted portions 23 and the side walls 11 of the side frames 10. Withthis configuration, since the height adjustment mechanism 50 is disposedbetween the slanted portions 23 and the side walls 11, it is possible toeffectively utilize the space between the slanted portions 23 and theside walls 11.

According to this embodiment, in particular, the slanted portion 23includes a first slanted portion 23A extending from the end portion ofthe middle portion 22 and having a large slant angle with respect to thehorizontal plane, and a second slanted portion 23B extending from thelaterally outward end portion of the first slanted portion 23A andhaving a smaller slant angle with respect to the horizontal plane thanthat of the first slanted portion 23A. With this configuration in whichthe slanted portion 23 consists of the two slanted portions 23A, 23B, itis possible to leave a space between the slanted portion 23 and theheight adjustment mechanism 50. Therefore, interference between theslanted portion 23 and the height adjustment mechanism 50 can besuppressed.

It is to be noted that the height adjustment mechanism 50 is provided inproximity of the right and left side frames 10, and mainly includes inpairs a front link 51, a rear link 52, an upper link 53, a slider SL,and a spiral spring 54. The front link 51 and the rear link 52 are eachshaped like a “V”, and the lower ends thereof are rotatably connected toa front end portion and a rear end portion of the slider SL,respectively, whereas center portions (portions corresponding to valleysof Vs) are rotatably connected to the side frame 410.

Namely, a four-bar linkage is formed by the side frame 10, the lowerhalf portions of the front link 51 and the rear link 52, and the sliderSL, so that tilting the front link 51 and the rear link 52 in thefrontward direction or in the rearward direction causes the side frame10 to move upward or downward. Further, upper end portions of the frontlink 51 and the rear link 52 are rotatably connected to the upper link53.

The spiral spring 54 is a spring for urging the front link 51 in adirection to raise the front link 51; the spiral spring 54 is disposedlaterally inward of the front link 51, and the end thereof that islocated closer to the center of the spiral spring 54 is engaged with aspring engagement portion 14 formed on the side frame 10 whereas theouter end thereof is engaged with a rotary shaft for the front link 51and the upper link 53. Further, the front link 51 is configured to betilted in the frontward direction or in the rearward direction when adriving force from an operating lever (not shown) is transmitted to thefront link 51.

In the height adjustment mechanism 50 configured as described above, ifthe side frame 10 is to be lowered, the occupant manipulates theoperating lever in one direction to tilt the front link 51 in arearward-and-downward direction against the urging force of the spiralspring 54 to thereby lower the side frame 10. On the contrary, if theside frame 10 is to be lifted, the occupant manipulates the operatinglever in the other direction to tilt the front link 51 in afrontward-and-upward direction. In this operation, when the occupantmanipulates the operating lever in the other direction, the manipulationof the operating lever is assisted by the spiral spring 54.

As seen in FIGS. 3(a) and 5(a) and 5(b), the engagement portion 21includes a base portion 21 b configured to be bent in an approximatelyC-shaped configuration, a straight portion 21 c extending in thefront-rear direction from the base portion 21 b, and an end portion 21 aconfigured to be bent laterally inward from the straight portion 21 c,and is formed as a whole to have an approximately C-shaped configurationwhich opens laterally inward. Further, the engagement portion 21provided in the front-side cushion spring 20A is formed such that theend portion 21 a thereof faces approximately frontward, and theengagement portion 21 provided in the rear-side cushion spring 20B isformed such that the end portion 21 a thereof faces approximatelyrearward.

The two cushion springs 20A, 20B are respectively disposed frontward andrearward of an occupant's seating position (i.e., the position to whicha load from the occupant is most heavily applied during the driving ofthe automobile). Accordingly, when the occupant sits on the seat cushionS1, the load from the occupant is applied to the front-side andrear-side cushion springs 20A, 20B such that the cushion springs 20A,20B move in opposite directions away from each other. However, even withthis configuration, since the end portion 21 a of the front-sideengagement portion 21 faces frontward and the end portion 21 a of therear-side engagement portion 21 faces rearward as described above, it ispossible to favorably keep the engagement between the cushion springs 20and the side frames 10. Further, even if a large frontward force isapplied from the occupant to the front-side cushion spring 20A in acollision of the automobile, it is possible to favorably keep theengagement between the cushion springs 20 and the side frames 10.

Further, the front-side cushion spring 20A is disposed at a positionrearward of the front end portion of the height adjustment mechanism 50and frontward of a center C of the height adjustment mechanism 50 in thefront-rear direction, and is engaged with the front-side engagementopening 12A from the rear side of the front-side engagement opening 12Abecause the end portion 21 a of the engagement portion 21 facesapproximately frontward. With this configuration, it is possible toprevent the front-side cushion spring 20A from interfering with thestructure in the vicinity of the front end portion of the heightadjustment mechanism 50 (e.g., spiral spring 54) when the front-sidecushion spring 20A is engaged with the front-side engagement opening12A.

Further, the rear-side cushion spring 20B is disposed at a positionfrontward of the rear end portion of the height adjustment mechanism 50and rearward of the center C of the height adjustment mechanism 50 inthe front-rear direction, and is engaged with the rear-side engagementopening 12B from the front side of the rear-side engagement opening 12Bbecause the end portion 21 a of the engagement portion 21 facesapproximately rearward. With this configuration, it is possible toprevent the rear-side cushion spring 20B from interfering with thestructure in the vicinity of the rear end portion of the heightadjustment mechanism 50 (e.g., rear link 52) when the rear-side cushionspring 20B is engaged with the rear-side engagement opening 12B.

Each engagement portion 21 is inserted in the engagement opening 12A,12B from below and engaged with the engagement opening 12A, 12B. Sincethe engagement portion 21 of the cushion spring 20 is engaged with theengagement opening 12A, 12B from below, it is possible to prevent thedistal end portion (laterally inward end portion) of the upper flangeportion 12 from receiving a load from the cushion spring 20, forexample, as compare with the configuration in which the engagementportion of the cushion spring is engaged with the engagement openingfrom above.

Further, the wire diameter of the front-side cushion spring 20A isgreater than that of the rear-side cushion spring 20B. With thisconfiguration, even if a larger load is applied from the occupant duringthe braking or the like to the front-side cushion spring 20A than to therear-side cushion spring 20B, the load can be favorably received by thecushion spring 20A having the large wire diameter.

In accordance with the cushion springs 20A, 20B having different wirediameters, the front-side engagement opening 12A and the rear-sideengagement openings 12B may be different in size, and the front-siderecess portion 12C and the rear-side recess portion 12C may be differentin size. As an alternative, in accordance with the size of the cushionspring 20A having a large wire diameter, the front-side engagementopening 12A and the rear-side engagement opening 12B may be formed inthe same in size, and the recess portions 12C may be formed in the samein size.

Further, as seen in FIGS. 2 and 4, a cover member 70 for covering thereclining mechanism RL (recess portion 12C) is provided on top of theengagement portion 21 engaged with the rear-side engagement opening 12B.With this configuration, since the engagement portion 21 can besandwiched between the recess portion 12C and the cover member 70, it ispossible to favorably keep the engagement between the rear-side cushionspring 20B and the rear-side engagement opening 12B.

Although the first embodiment of the present invention has beendescribed above, the present invention is not limited to this embodimentand may be carried out into practice in various other ways, as will bedescribed below.

In the above-described first embodiment, the cushion spring 20 in theform of an S-shaped spring is exemplified as an elastic member. However,the present invention is not limited to this configuration; for example,any known spring other than the S-shaped spring may be used as long asit is made by bending a wire, and alternatively rubber may be used.

In the above-described first embodiment, the present invention isapplied to the side frames 10 of the seat cushion frame F1. However, thepresent invention is not limited to this specific configuration; forexample, the present invention may be applied to the side frames of theseat back frame.

In the above-described first embodiment, the cushion springs 20 isattached to the upper flange portions 12. However, the present inventionis not limited to this specific configuration; for example, the cushionsprings may be attached to the lower flange portions.

In the above-described first embodiment, the first engagement openingA1, B1 and the second engagement opening A2, B2 are arranged in line inthe front-rear direction. However, the present invention is not limitedto this specific configuration; for example, the first engagementopening and the second engagement opening may be arranged in line in adirection that is slanted with respect to the front-rear direction.

In the above-described first embodiment, the cover member 70 for thereclining mechanism RL is placed on top of the engagement portion 21.However, the present invention is not limited to this specificconfiguration, and any cover member may be employed.

In the above-described first embodiment, the reinforcement rod 60 isexemplified as a reinforcement member. However, the present invention isnot limited to this specific configuration; for example, a reinforcementmember having an L-shaped section or a U-shaped section may be employed.

In the above-described first embodiment, the car seat S used for anautomobile is exemplified as an example of a vehicle seat. However, thepresent invention is not limited to the car seat, and may be applied toother vehicle seat, such as a seat for a ship or an aircraft.

Second Embodiment

With reference to FIGS. 6 to 11, the second embodiment of the presentinvention will be described below. Constituent elements similar to thosepreviously described in the first embodiment are denoted by the samereference numerals and detailed description thereof will be omitted.

A seat frame F as shown in FIG. 6 is embedded in the seat cushion S1(see FIG. 1) and the seat back S2 (see FIG. 1). The seat frame F mainlyincludes a seat cushion frame F1 constituting a frame of the seatcushion S1, and a seat back frame F2 constituting a frame of the seatback S2. The seat cushion S1 is configured such that the seat cushionframe F1 is covered with a seat cushion pad 200 (see FIG. 7) as anexample of a cushion pad made of a cushion material such as urethanefoam, and a skin material 300 (see FIG. 9) made of synthetic leather orfabric. The seat back S2 is configured such that the seat back frame F2covered with a seat back pad made of a cushion material, and a skinmaterial made of synthetic leather or fabric.

A seat cushion frame F1 is a frame in the shape of an approximatelyrectangular configuration, and is installed on sliders SL; the slidersSL are respectively supported by a pair of right and left slide rails SRprovided on a floor of an automobile so as to be slidable in thefront-rear direction with respect to the slide rails SR. Accordingly,the position of the car seat S is adjustable in the front-reardirection.

A lower portion of the seat back frame F2 is rotatably connected to arear portion of the seat cushion frame F1 via a reclining mechanism RL.Accordingly, the seat back S2 is tiltable in the front-rear directionwith respect to the seat cushion S1.

Next, the seat cushion frame F1 and the seat cushion pad 200 will bedescribed in detail.

The seat cushion frame F1 mainly includes a pair of right and left sideframes 10, two S-shaped springs 120 (as an example of an elastic member)run between the right and left side frames 10, a pan frame 130connecting front portions of the side frames 10, and a cylindricalpipe-shaped connecting pipe 140 connecting rear end portions of the sideframes 10.

The right and left side frames 10 are frames extending in the front-reardirection and made of metal: the right and left side frames 10 arelaterally spaced apart from each other. The pan frame 130 is disposed atan approximately front-half portion between the right and left sideframes 10, and the two S-shaped springs 120 spaced apart from each otherin the front-rear direction (i.e., transverse direction of the S-shapedspring 120) are attached to an approximately rear-half portion betweenthe right and left side frames 10.

Each of the S-shaped springs 120 is a long spring extending laterallywith a plurality of turns made in the front-rear direction. To be morespecific, the S-shaped spring 120 includes a plurality of front-sidebent portions 121 each having an approximately circular arcconfiguration which protrudes frontward, a plurality of rear-side bentportions 122 each having an approximately circular arc configurationwhich protrudes rearward, a plurality of connecting portions 123 eachhaving an approximately linear configuration and configured to connectthe front-side bent portion 121 and the rear-side bent portion 122, andengagement portions 124 each formed at the outermost front-side bentportion 121 or the outermost rear-side bent portion 122 and configuredto be engageable with the side frame 10.

The pan frame 130 is an approximately box-like member which opens upwardand rearward.

The right and left side frames 10, the pan frame 130, and the twoS-shaped springs 120 are covered with the seat cushion pad 200 as shownin FIG. 7. Accordingly, the seat cushion pad 200 is supported by theside frames 10, the pan frame 130, and the S-shaped springs 120 from thelower side (reverse side) of the seat cushion pad 200.

As seen in FIGS. 7 to 9, a skin attachment wire 210 (as an example of askin attachment member) is provided at a bottom rear portion of the seatcushion pad 200; engagement portions 310 provided at an end portion ofthe skin material 300 are engageable with the skin attachment wire 210.With this configuration, as compared with the conventional configurationin which the skin attachment member is provided on the frame, it ispossible to simplify the frame structure of the seat cushion frame F1.

Three engagement portions 310 are provided laterally spaced apart fromeach other at the rear end portion of the skin material 300; the frontend of each engagement portion 310 is bent along the peripheral surfaceof the skin attachment wire 210 (i.e., engaged portion 212 to bedescribed later) so as to be engageable with the skin attachment wire210. The engagement portions 310 are also provided at another endportion of the skin material 300 where necessary.

To be more specific, three recess portions 220 in the shape of arectangle extending long in the lateral direction are provided at thebottom rear portion of the seat cushion pad 200; the recess portions 220are laterally spaced apart (in a direction in which the skin attachmentwire 210 extends) from each other, and the skin attachment wire 210 isembedded in the seat cushion pad 200 so as to extend laterally throughthe three recess portions 220. More specifically, the skin attachmentwire 210 is a rod-like member extending laterally and made of metal; theskin attachment wire 210 includes four retention portions 211 embeddedand retained in the seat cushion pad 200, and three engaged portions 212respectively exposed in the recess portions 220 and engaged with theengagement portions 310 of the skin material 300.

With this configuration in which the skin attachment wire 210 isembedded in the seat cushion pad 200, the skin attachment wire 210 doesnot protrude from the lower surface of the seat cushion pad 200, so thatthe seat cushion pad 200 can be downsized.

Further, the two laterally outermost retention portions 211 among thefour retention portions 211 are embedded and retained in two outerportions 231 located laterally outside the three recess portions 220,whereas the two center retention portions 211 are embedded and retainedin the two middle portions 232 formed between the three recess portions220. Accordingly, since not only the two outer portions 231 but also thetwo middle portions 232 retain the skin attachment wire 210, forexample, as compared with an embodiment in which the recess portion isone groove elongated in the lateral direction, the number of portionsfor retaining the skin attachment wire 210 can be increased, so thatdeformation of the skin attachment wire 210 can be suppressed.

Further, a coarse blanket 240 as an example of a sheet member isprovided on the reverse surface of the seat cushion pad 200. The coarseblanket 240 is a fabric for improving the rigidity of the seat cushionpad 200 and preventing the reverse surface of the seat cushion pad 200from being torn as well as for suppressing noise from the road surface;three exposure openings 241 as an example of cutaway portions are formedat the rear portion of the coarse blanket 240.

In order to expose the recess portions 220 of the seat cushion pad 200to view, the exposure openings 241 are respectively formed in shapesmatching the shapes of the recess portions 220 at positionscorresponding to the recess portions 220. Further, portions of thecoarse blanket 240 located between the exposure openings 241 are formedas two middle reinforcement portions 242 disposed to overlap the twomiddle portions 232. With this configuration in which the middlereinforcement portions 242 are provided to overlap the middle portions232, for example, as compared with the structure in which the exposureopening is formed as one opening elongated in the lateral direction, therigidity of the middle portions 232 can be reinforced by the middlereinforcement portions 242. Accordingly, deformation of the skinattachment wire 210 can be further suppressed.

Further, the skin attachment wire 210 is disposed so as not to overlapthe S-shaped springs 120 as viewed from the lower side. Accordingly, thework for attaching the skin material 300 can be eased because when theengagement portions 310 of the skin material 300 are attached to theskin attachment wire 210 from the lower side, the S-shaped springs donot obstruct the attachment.

Especially, in this embodiment, the skin attachment wire 210 is disposedrearward (outside in the transverse direction) of the two S-shapedsprings 120. Accordingly, even when the engagement portions 310 of theskin material 300 approach the skin attachment wire 210 from the rearside, as the S-shaped springs 120 are not present at the rear side ofthe skin attachment wire 210, the work for attaching the skin material300 can be eased further, in comparison, for example, with the structurein which the skin attachment wire is disposed between the two S-shapedsprings.

Further, the middle portions 232, the middle reinforcement portions 242,and the front-side bent portions 121 (i.e., bent portions protruding ina direction away from the recess portions 220) of the S-shaped spring120 are arranged in the same position in the lateral direction (i.e.,longitudinal direction of the S-shaped spring 120). More specifically, aportion of each middle portion 232, a portion of each middlereinforcement portion 242, and a portion of the front-side bent portionare arranged in the same lateral position.

With this configuration, since the middle portion 232 and the middlereinforcement portion 242 are disposed in an open portion of theS-shaped spring 120, it is possible to enhance the rigidity of a portionof the seat cushion pad 200 which is located in an open space (i.e., aportion located between two adjacent rear-side bent portions 122) of theopen portion of the S-shaped spring 120, in comparison, for example,with the configuration in which the recess portion is formed as onegroove elongated in the lateral direction.

First Modified Embodiment

Next, a first modified embodiment will be described in detail withreference made to the drawings where necessary. As the first modifiedembodiment is a modification of the structure in the vicinity of theskin attachment wire according to the above-described second embodiment,constituent elements similar to those previously described in the secondembodiment are denoted by the same reference numerals and detaileddescription thereof will be omitted.

As seen in FIG. 10, the skin attachment wire 410 according to the firstmodified embodiment is different from that of the second embodiment inthat each of the retention portions 411 corresponding to the middleportions 232 is formed to protrude frontward to form a U-shapedconfiguration. Further, the S-shaped spring 420 according to the firstmodified embodiment is disposed such that the two rear-side bentportions 122 among the plurality of rear-side bent portions 122 arelocated directly under the retention portions 411 and thus arranged inthe same lateral positions as the middle portions 232.

With this configuration in which the S-shaped spring 420 is disposeddirectly under the retention portions 411 of the skin attachment wire410, even if a local load is applied in the vicinity of the retentionportion 411 of the skin attachment wire 410 of the seat cushion pad 200,the S-shaped spring 120 can suppress sinking of the skin attachment wire410. Accordingly, it is possible to prevent the engagement portion 310from coming off the skin attachment wire 410 due to sinking of the skinattachment wire 410.

Second Modified Embodiment

Next, a second modified embodiment will be described in detail withreference to the drawings where necessary. As the second modifiedembodiment is a modification of the structure in the vicinity of theskin attachment wire according to the above-described second embodiment,constituent elements similar to those previously described in the secondembodiment are denoted by the same reference numerals and detaileddescription thereof will be omitted.

As seen in FIGS. 11(a) and (b), the skin attachment wire 510 accordingto the second modified embodiment is formed to have a plurality of turnsmade in the upper-lower direction; a part of the skin attachment wire510 constitutes retention portions 511 embedded in the seat cushion pad200, while the rest of the skin attachment wire 510 constitutes engagedportions 512 protruding downward from the lower surface of the seatcushion pad 200 (more specifically, the coarse blanket 240) and exposedoutside. The engaged portions 512 are located at positions lower thanthe S-shaped spring 120 for supporting the seat cushion pad 200 from thelower side of the seat cushion pad 200.

With this configuration in which the engaged portions 512 are located atpositions lower than the S-shaped spring 120, the attachment of theengagement portions 310 of the skin material 300 to the engaged portions512 is easily performed. Accordingly, the work for attaching the skinmaterial 300 can be eased further.

Although the second embodiment and the modified embodiments thereof havebeen described above, the present invention is not limited to theseconfigurations and may be carried out into practice in various otherways, as will be described below.

In each of the above-described embodiments, the seat cushion pad 200 isexemplified as an example of a cushion pad. However, the presentinvention is not limited to this configuration, and a seat back pad maybe employed as the cushion pad.

In each of the above-described embodiments, the skin attachment wire210, 410, 510 is provided at the rear portion of the seat cushion pad200. However, the present invention is not limited to thisconfiguration; the skin attachment member may be provided at anyposition as long as it is provided at the reverse side of the cushionpad.

In each of the above-described embodiments, the wire (skin attachmentwire 210 and the like) is exemplified as an example of the skinattachment wire. However, the present invention is not limited to thisconfiguration; for example, a cylindrical pipe member or apolygonal-shaped rod-like member may be used.

In each of the above-described embodiments, the coarse blanket 240 isexemplified as an example of a sheet member. However, the presentinvention is not limited to this configuration; other fabric may be usedas long as it is a sheet-like member.

In the above-described second embodiment, the plurality of recessportions 220 are arranged in line in the lateral direction. However, thepresent invention is not limited to this configuration; if the skinattachment member extends, for example, along a circular arc, theplurality of recess portions may be arranged in line along the circulararc. Further, the number of recess portions is not limited to thespecific number as disclosed in the above-described embodiment, and anynumber of recess portions may be provided.

In the above-described second embodiment, the openings (exposureopenings 241) are exemplified as an example of cutaway portions.However, the present invention is not limited to this configuration; forexample, cutaway portions which open at an end portion of the sheetmember may be provided.

In the above-described first modified embodiment, the retention portions411 of the skin attachment wire 410 are modified so that the S-shapedspring 420 is disposed directly under the retention portions 411.However, the present invention is not limited to this configuration; forexample, the shape of the S-shaped spring may be modified so that theS-shaped spring is disposed directly under the engaged portions of theskin attachment member.

In each of the above-described embodiments, the S-shaped spring 120 isexemplified as an example of an elastic member. However, the presentinvention is not limited to this configuration; for example, other wiresprings and plate springs, and the like may be used. However, in theconfiguration utilizing the S-shaped spring, the seat cushion pad can befavorably supported, for example, as compared with the configuration inwhich a straight wire spring is employed.

In each of the above-described embodiments, the S-shaped spring 120(elastic member) is formed to extend laterally. However, the presentinvention is not limited to this configuration; as long as the elasticmember extends in a direction from one end to another end of the cushionpad, the elastic member may extend, for example, in the front-reardirection.

In the above-described embodiment, the car seat S used for an automobileis exemplified as an example of a vehicle seat. However, the presentinvention is not limited to the car seat, and may be applied to othervehicle seat, such as a seat for a ship or an aircraft.

Third Embodiment

With reference to FIGS. 12 to 16, the second embodiment of the presentinvention will be described below. Constituent elements similar to thosepreviously described in the above-described first embodiment are denotedby the same reference numerals and detailed description thereof will beomitted.

A seat frame F as shown in FIG. 12 is embedded in the seat cushion S1(see FIG. 1) and the seat back S2 (see FIG. 1). The seat frame F mainlyincludes a seat cushion frame F1 constituting a frame of the seatcushion S1, and a seat back frame F2 constituting a frame of the seatback S2. The seat cushion S1 is configured such that the seat cushionframe F1 is covered with a seat cushion pad 700 (see FIG. 13) made of acushion material such as urethane foam, and a skin material 800 (seeFIG. 15) made of synthetic leather or fabric. The seat back S2 isconfigured such that the seat back frame F2 is covered with a seat backpad made of a cushion material, and a skin material made of syntheticleather or fabric.

A seat cushion frame F1 is a frame in the shape of an approximatelyrectangular configuration, and is installed on sliders SL; the slidersSL are respectively supported by a pair of right and left slide rails SRprovided on a floor of an automobile so as to be slidable in thefront-rear direction with respect to the slide rails SR. Accordingly,the position of the car seat S is adjustable in the front-reardirection.

A lower portion of the seat back frame F2 is rotatably connected to arear portion of the seat cushion frame F1 via a reclining mechanism RL.Accordingly, the seat back S2 is tillable in the front-rear directionwith respect to the seat cushion S1.

Next, the seat cushion frame F1 and the seat cushion pad 700 will bedescribed in detail.

The seat cushion frame F1 mainly includes a pair of right and left sideframes 10, two S-shaped springs 620 (as an example of an elastic member)run between the right and left side frames 10, a pan frame 630connecting front portions of the side frames 10, and a connecting pipe640 connecting rear end portions of the side frames 10.

The right and left side frames 10 are frames extending in the front-reardirection and made of metal: the right and left side frames 10 arelaterally spaced apart from each other. The pan frame 630 is disposed atan approximately front-half portion between the right and left sideframes 10, and the two S-shaped springs 620 are attached to anapproximately rear-half portion between the right and left side frames10 with these S-shaped springs 120 spaced apart from each other in thefront-rear direction.

Each of the S-shaped springs 620 is a spring extending long in thelateral direction with a plurality of turns made in the front-reardirection (i.e., transverse direction of the S-shaped spring 620). To bemore specific, the S-shaped spring 620 includes a plurality offront-side bent portions 621 each having an approximately circular arcconfiguration which protrudes frontward, a plurality of rear-side bentportions 622 each having an approximately circular arc configurationwhich protrudes rearward, a plurality of connecting portions 623 eachhaving an approximately linear configuration and configured to connectthe front-side bent portion 621 and the rear-side bent portion 622, andengagement portions 624 each formed at the outermost front-side bentportion 621 or the outermost rear-side bent portion 622 and configuredto be engageable with the side frame 10.

The pan frame 630 is an approximately box-like member which opens upwardand rearward.

The right and left side frames 10, the pan frame 630, and the twoS-shaped springs 620 are covered with the seat cushion pad 700 as shownin FIG. 13(a). Accordingly, the seat cushion pad 700 is supported by theside frames 10, the pan frame 630, and the S-shaped springs 620 from thelower side of the seat cushion pad 700.

As seen in FIGS. 13(a) and 13(b), a through-opening 710 for inserting aharness member 920 of a seating sensor 900 is formed in an approximatelycenter portion of the seat cushion pad 700 to pierce through the seatcushion pad 700 in the upper-lower direction; the seating sensor 900 isconfigured to detect an occupant seating on the seat cushion S1. Thethrough-opening 710 is a rectangular-shaped opening with an upper-sideopening 711 and a lower-side opening 712, and formed such that thelower-side opening 712 is larger than the upper-side opening 711.

With this configuration, for example, as compared with the configurationin which the through-opening is formed to extend vertically straight,the weight of the seat cushion pad 700 can be reduced for the amountcorresponding to the extended lower-side portion of the through-opening710. Further, since the upper-side opening 711 of the through-opening710 is smaller, it is possible to reduce uncomfortable feelingexperienced by the occupant when he/she sits on the seat cushion pad 700and feels the presence of the through-opening 710, for example, ascompared with the configuration in which the upper-side opening of thethrough-opening is enlarged to reduce the weight.

As seen in FIG. 14, the through-opening 710 is disposed in the sameposition in the front-rear direction as the front-side S-shaped spring620 among the two front and rear S-shaped springs 620. To be morespecific, a portion of the through-opening 710 and a portion of thefront-side S-shaped spring 620 are arranged in the same position in thefront-rear direction (i.e., on one vertical plane PF extending in thelateral direction). In other words, the through-opening 710 and thefront-side S-shaped spring 620 are arranged to intersect one verticalplane extending in the lateral direction (i.e., longitudinal directionof the S-shaped spring 620).

With this configuration, since a portion around the through-opening 710is supported by the S-shaped spring 620, deformation of thethrough-opening 710 can be suppressed and a load applied to the harnessmember 920 can be reduced. Further, since the through-opening 710 isprovided in the position corresponding to the front-side S-shaped spring620, which is less likely to receive a load from the occupant than therear-side S-shaped spring 620 where a large load is applied from theoccupant, for example, as compared with the configuration in which thethrough-opening is provided in the position corresponding to therear-side S-shaped spring, deformation of the through-opening 710 can befurther suppressed and thus a load applied to the harness member 920 canbe further reduced.

The through-opening 710 is disposed in a position not overlapping theS-shaped spring 620 as viewed from the lower side, more specifically, ata position between a pair of connecting portions 623 of the S-shapedspring 620. With this configuration, the work for inserting the harnessmember 920 into the through-opening 710 can be eased because theS-shaped spring 620 does not obstruct the work. Further, since thethrough-opening 710 and the S-shaped spring 620 do not overlap eachother, interference between the harness member 920 and the S-shapedspring 620 can be suppressed.

The pair of connecting portions 623 are formed to extend along theperipheral edge of the rectangular-shaped through-opening 710 andadjacent to the through-opening 710. With this configuration, theportion around the through-opening 710 can be favorably supported by theconnecting portions 623 of the S-shaped spring 620.

Further, a portion of the S-shaped spring 620 which surrounds thethrough-opening 710, namely, a recess-shaped portion formed by afront-side bent portion 621 and a pair of connecting portions 623 isformed to open rearward. With this configuration, since the portion ofthe S-shaped spring 620 which surrounds the through-opening 710 opensrearward, even if the through-opening 710 and the harness member 920located in the through-opening 710 are pulled and moved rearward whenthe rear portion of the seat cushion pad 700 is deeply sunk by the loadfrom the occupant, interference between the harness member 920 and theS-shaped spring 620 can be suppressed.

As seen in FIGS. 12 and 15, the connecting pipe 640 is a cylindricalpipe, and a skin attachment member 650 is fixed to an approximatelycenter portion of the connecting pipe 640 by welding or the like. Theskin attachment member 650 is made by bending a cylindrical columnarmember made of metal, and mainly includes two engaged portions 651, arecess-shaped portion 652 provided between the engaged portions 651, andattachment portions 653 provided laterally outside the respectiveengaged portions 651.

The engaged portions 651 are rod-like portions extending in the lateraldirection and located laterally spaced apart from each other atpositions away from the connecting pipe 640. Two engagement portions 810provided on the skin material 800 are respectively engaged with theengaged portions 651.

The recess-shaped portion 652 is formed to open downward (in a directionopposite to the connecting pipe 640), and both end portions of therecess-shaped portion 652 are respectively connected to a laterallyinner end portion of the engaged portions 651.

The attachment portion 653 extends upward (toward the connecting pipe640) from a laterally outer end portion of each of the engaged portions651, and a distal end of the attachment portion 653 is bent along theperipheral surface of the connecting pipe 640.

Further, the recess-shaped portion 652 and the attachment portions 653are fixed to the connecting pipe 640 by welding or the like. With thisconfiguration, the skin attachment member 650 can be fixed firmly to theconnecting pipe 640 at three portions, for example, as compared with theconfiguration in which both ends of a U-shaped skin attachment member isfixed to the connecting pipe (at two portions).

Disposed inside the recess-shaped portion 652 is a harness member 940for a heater, for instance. For example, in a structure in which bothends of the U-shaped skin attachment member is fixed to the connectingpipe, it is necessary that the harness member be inserted between theskin attachment member and the connecting pipe, with the result that thewiring work for the harness member will be complicated. In contrast, ifthe center portion of the skin attachment member 650 is formed as therecess-shaped portion 652 according to this embodiment, the wiring workfor the harness member 940 can be eased because the harness member 940can be simply inserted to the inside (toward the connecting pipe 640)from an opening of the recess-shaped portion 652.

The two engagement portions 810 are located laterally spaced apart atthe rear-side end portion of the skin material 800; the distal end ofeach of the engagement portions 810 is bent along the peripheral surfaceof the engaged portion 651 so as to be engageable with the engagedportion 651. The engagement portions 810 are also provided at other endportions of the skin material 800 where necessary. Further, a portion820 of the skin material 800 which is located between theabove-described two engagement portions 810 faces the harness member940. With this configuration, the skin material 800 can prevent theoccupant from touching the harness member 940.

Although the third embodiment has been described above, the presentinvention is not limited to this specific configuration and may becarried out into practice in various other ways, as will be describedbelow.

In the above-described third embodiment, the through-opening 710 isdisposed between the pair of connecting portions 623. However, thepresent invention is not limited to this configuration; for example, thethrough-opening 710 may be disposed in a space surrounded by a U-shapedfront-side bent portion 621 or in a space between a pair of rear-sidebent portions 622. Further, it is not necessary that the through-opening710 be disposed within the width of the S-shaped spring 620 in thefront-rear direction; for example, as seen in FIG. 16, thethrough-opening 710 may be disposed in a position outside the width ofthe S-shaped spring 620 in the front-rear direction. In other words, thethrough-opening 710 and the S-shaped spring 620 are arranged tointersect one vertical plane PF extending in the lateral direction.

In the above-described third embodiment, the S-shaped spring 620(elastic member) is formed to extend laterally. However, the presentinvention is not limited to this configuration; as long as the elasticmember extends in a direction from one end to another end of the seatcushion pad, the elastic member may extend in any direction, forexample, in the front-rear direction.

In the above-described third embodiment, the through-opening 710 isformed as a rectangular-shaped opening. However, the present inventionis not limited to this configuration; for example, the through-openingmay be a circular opening or a polygonal opening other than therectangular-shaped opening.

In the above-described third embodiment, the S-shaped spring 620 isexemplified as an example of an elastic member. However, the presentinvention is not limited to this configuration; for example, other wiresprings and plate springs, and the like may be used. However, in theconfiguration utilizing the S-shaped spring, the seat cushion pad can befavorably supported, for example, as compared with the configuration inwhich a straight wire spring is employed.

In the above-described third embodiment, the car seat S used for anautomobile is exemplified as an example of a vehicle seat. However, thepresent invention is not limited to the car seat, and may be applied toother vehicle seat, such as a seat for a ship or an aircraft.

1. A vehicle seat comprising: right and left side frames; and an elasticmember run between the right and left side frames and configured tosupport an occupant, wherein the right and left side frames comprise:side walls disposed opposite to each other in a lateral direction; andflange portions respectively extending laterally inward from the sidewalls, wherein the elastic member is attached to the flange portions.2-20. (canceled)